The invention relates to a hydraulic dashpot for pipeline systems comprising a piston mounted for displacement in a fluid pressure cylinder, connecting members at the fluid pressure cylinder and a piston rod connected to the piston, a storage chamber for hydraulic fluid present in cylinder chambers on opposite sides of the piston, and the piston accommodating a main control valve having a valve seat body in which are displaceably mounted and spring-biased two opposed piston-type valve members each having at least one throttle bore.